Power semiconductor devices are currently used to switch large amounts of current at moderate voltage levels. They are required to be thermally coupled to relatively large heat sinks, which are bulky and require assembly. Often, there also has to be a layer of electrical insulation between the power device and the heat sink for safety. The layer of electrical insulation may be provided by the package molding, or by a sheet of dielectric material disposed between a metal part of the package (e.g., exposed die paddle) and the heat sink. The first approach has relatively poor thermal conductivity. The second approach makes the assembly of the heat sink more complex.